Effect

Generation IV

Healing Wish causes the user to faint, then immediately switches in the new Pokémon. The new Pokémon's HP is restored and it is cured of any status conditions upon being sent out. Healing Wish will fail if the player has no other conscious Pokémon in their party.

Generation V onward

The receiving Pokémon is now sent out at the end of the turn rather than immediately sending it out.

In other games

Healing Wish reduces the user's HP to 1, and restores all the HP and PP of team members in the same room as the user. It also removes any status conditions on those Pokémon and breaks any move seals caused by seal traps.

In the anime

Jirachi flies into the sky, and its body starts to glow white. It then lets out a burst of light blue, sparkling lights, that rain down onto Jirachi's allies, healing them. After using the move, Jirachi faints.